Mainspring barrel



March 17, 1931.

A. F. KENDLE 96,374

MAINSPRING BARREL Filed Feb. 15, 1930 A. F. KENDLE Patented Mar. 17, 1931 UNITED STATES PATENT? OFFICE MAIN SPRING BARREL Application filed February 13, 1930. Serial No. 428,031.

My invention relates to mainsp-ring barrels, its primary object being the provision of a connection between the mainspring barrel and the main time drive wheel, the connection facilitating the easy assembly and disassembly of these two members.

Another of my objects is the provision of an assembly of the mainspring barrel and the main drive wheel which is so designed as to eliminate the accidental breakage of teeth on the drive wheel when the spring becomes suddenly released through breakage of the spring or through breakage of the spring connections.

Another of my objects is the provision of a connection between the mainspring barrel and the main drive wheel whereby the replace ment of springs becomes a matter of extreme simplicity.

Having in view these objects and others which will be pointed out in the following description, I will now refer to the drawings, in which Figure 1 is a plan view of the assembly of the main drive wheel with the mainspring barrel as seen from the side of the drive wheel.

Figure 2 is a plan view of the main drive wheel, the view being taken from the same side as that in Figure 1.

Figure 3 is a plan view of the mainspring barrel with the teeth which are designed to interlock with the main drive wheel.

Figure 4 is a view in perspective of a fragment of the mainspring barrel and showing in enlarged scale the interlocking teeth.

Figure 5 is a view in slight perspective of a fragment of the main drive wheel showing in enlarged scale the notch in which the teeth of the mainspring barrel are adapted to latch.

Figure 6 is a similar view of a fragment of the main drive wheel with the aperture shown as seen from the side opposite that shown in Figures 2 and 5.

My invention is designed initially and primarily for use in the clock which is shown and described in my prior Patent No. 1,575,- 063, granted March 2, 1926. The invention, however, is capable of use in connection with any and all clocks and in fact with any and all spring motor devices. While I shall describe it with particular reference to its use with a clock and especially with reference to its use in the clock of my prior patent, I do not wish to be restricted to that use.

The device includes the usual main time drive wheel 10 and the usual spring barrel 11 which supports the spring 12. In prior constructions, however, the barrel 11 is permanently secured to the drive wheel thus making the replacement of springs an exceedingly difficult ob for skilled watchmakers. Another objection to the prior constructions is that the breaking of the spring usually results in a reaction which breaks the gear teeth of either the drive wheel or of the driven wheel or both.

The barrel 11 in the present instance is provided with a plurality of teeth 13 as best shown in Figure 4. These teeth have an outer face which lies in a plane parallel to the plane of one of the edges of the barrel 11. At one side the tooth joins the barrel in an acute angle and at the other side the junction is in the form of an obtuse angle. The direction of the teeth is governed by the direction of tension of the spring 12. The main time drive wheel 10 is provided with a plurality of apertures 14 which correspond in number and position with the number and position of the teeth 13 on the barrel 11. Each slot or aperture 14 is provided with a beveled ledge 14 as shown in Figure 5. The assembly of the barrel with the wheel is simply a matter of matching the teeth 13 with the apertures 14 and giving the two a slight twist with reference to each other which will firmly latch the two together. A slight twist in the opposite direction will release them.

It is my purpose to provide replacement springs in the barrels so that the repair man is not put to the necessity of setting the spring within the barrel. The repair man simply removes the old barrel of a damaged spring and inserts the new barrel with the new spring. In case of breakage of the spring the reaction caused by the breakage will release the connection between the barrel and the wheel so that the teeth of the wheel are not subjected to any stress.

Having thus decribed my invention in such full, clear, and exact terms that its construction and operation will be readily understood by others skilled in the art to which 5 it pertains, what I claim as new and desire to secure by Letters Patent of the United States is a In a spring motor, a spring barrel and a drive wheel, said drive wheel being provided with a plurality of slots arranged concentrically about the axis of said drive wheel, ledges within the slots of said drive wheel and a plurality of teeth projecting froman edge of said barrel, the number'and position of said teeth corresponding with the number and position of slots of said drive wheel, and tangentially inclined end members on said teeth adapted to be seated on said ledges.

In testimony whereof I affix my signature.

g9 ALBERT F. KENDLE. 

